1. Field of the Invention
The present invention relates to a used-can processing system and method for pelletizing used cans for reuse.
2. Description of the Related Art
Conventionally, drum cans formed of steel material have been used for accommodating, for example, liquid or solid waste for the purpose of storage or transportation. After use, such drum cans have been recycled after removal of contamination and impurities such as paint. Such removal of impurities and dirt has been performed by a method in which drum cans are washed by use of cleaning liquid, or a method in which abrasive is blasted to a surface to be treated. Therefore, after being used and subjected to impurity removal processing three times or so, drum cans become unusable because of decreased wall thickness.
In general, used drum cans are scrapped. Also, there has been proposed pelletization of used drum cans at a waste treatment plant and using the thus-produced pellets as a new material (see, for example, Japanese Patent Application Laid-Open (kokai) No. 10-57928. In the proposed recycling process, drum cans are cut into small pieces by use of a shredder, and the thus-produced small pieces are formed into granular pellets by use of a pelletizer.
However, the above-described conventional apparatus has a problem in that a used can such as drum can is difficult to catch by means of blade portions of the shredder, and therefore, cutting of the used can is not easy. Further, since producing cut pieces of uniform size is difficult, pellets produced by a pelletizer vary in size, whereby the commercial value of the thus-produced pellets decreases. Moreover, when a pelletizer is used to produce pellets of uniform size from cut pieces of varying sizes, the pelletizer requires a long time to complete the pelletization process, and therefore fails to perform an efficient pelletization process.